// CodeMirror, copyright (c) by Marijn Haverbeke and others
// Distributed under an MIT license: https://codemirror.net/LICENSE

(function(mod) {
    if (typeof exports == "object" && typeof module == "object") // CommonJS
        mod(require("../../lib/codemirror"));
    else if (typeof define == "function" && define.amd) // AMD
        define(["../../lib/codemirror"], mod);
    else // Plain browser env
        mod(CodeMirror);
})(function(CodeMirror) {
    "use strict";

    function wordRegexp(words) {
        return new RegExp("^((" + words.join(")|(") + "))\\b");
    }

    var wordOperators = wordRegexp(["and", "or", "not", "is"]);
    var commonKeywords = ["as", "assert", "break", "class", "continue",
        "def", "del", "elif", "else", "except", "finally",
        "for", "from", "global", "if", "import",
        "lambda", "pass", "raise", "return",
        "try", "while", "with", "yield", "in"];
    var commonBuiltins = ["abs", "all", "any", "bin", "bool", "bytearray", "callable", "chr",
        "classmethod", "compile", "complex", "delattr", "dict", "dir", "divmod",
        "enumerate", "eval", "filter", "float", "format", "frozenset",
        "getattr", "globals", "hasattr", "hash", "help", "hex", "id",
        "input", "int", "isinstance", "issubclass", "iter", "len",
        "list", "locals", "map", "max", "memoryview", "min", "next",
        "object", "oct", "open", "ord", "pow", "property", "range",
        "repr", "reversed", "round", "set", "setattr", "slice",
        "sorted", "staticmethod", "str", "sum", "super", "tuple",
        "type", "vars", "zip", "__import__", "NotImplemented",
        "Ellipsis", "__debug__"];
    CodeMirror.registerHelper("hintWords", "python", commonKeywords.concat(commonBuiltins));

    function top(state) {
        return state.scopes[state.scopes.length - 1];
    }

    CodeMirror.defineMode("python", function(conf, parserConf) {
        var ERRORCLASS = "error";

        var delimiters = parserConf.delimiters || parserConf.singleDelimiters || /^[\(\)\[\]\{\}@,:`=;\.\\]/;
        //               (Backwards-compatibility with old, cumbersome config system)
        var operators = [parserConf.singleOperators, parserConf.doubleOperators, parserConf.doubleDelimiters, parserConf.tripleDelimiters,
            parserConf.operators || /^([-+*/%\/&|^]=?|[<>=]+|\/\/=?|\*\*=?|!=|[~!@]|\.\.\.)/]
        for (var i = 0; i < operators.length; i++) if (!operators[i]) operators.splice(i--, 1)

        var hangingIndent = parserConf.hangingIndent || conf.indentUnit;

        var myKeywords = commonKeywords, myBuiltins = commonBuiltins;
        if (parserConf.extra_keywords != undefined)
            myKeywords = myKeywords.concat(parserConf.extra_keywords);

        if (parserConf.extra_builtins != undefined)
            myBuiltins = myBuiltins.concat(parserConf.extra_builtins);

        var py3 = !(parserConf.version && Number(parserConf.version) < 3)
        if (py3) {
            // since http://legacy.python.org/dev/peps/pep-0465/ @ is also an operator
            var identifiers = parserConf.identifiers|| /^[_A-Za-z\u00A1-\uFFFF][_A-Za-z0-9\u00A1-\uFFFF]*/;
            myKeywords = myKeywords.concat(["nonlocal", "False", "True", "None", "async", "await"]);
            myBuiltins = myBuiltins.concat(["ascii", "bytes", "exec", "print"]);
            var stringPrefixes = new RegExp("^(([rbuf]|(br)|(rb)|(fr)|(rf))?('{3}|\"{3}|['\"]))", "i");
        } else {
            var identifiers = parserConf.identifiers|| /^[_A-Za-z][_A-Za-z0-9]*/;
            myKeywords = myKeywords.concat(["exec", "print"]);
            myBuiltins = myBuiltins.concat(["apply", "basestring", "buffer", "cmp", "coerce", "execfile",
                "file", "intern", "long", "raw_input", "reduce", "reload",
                "unichr", "unicode", "xrange", "False", "True", "None"]);
            var stringPrefixes = new RegExp("^(([rubf]|(ur)|(br))?('{3}|\"{3}|['\"]))", "i");
        }
        var keywords = wordRegexp(myKeywords);
        var builtins = wordRegexp(myBuiltins);

        // tokenizers
        function tokenBase(stream, state) {
            var sol = stream.sol() && state.lastToken != "\\"
            if (sol) state.indent = stream.indentation()
            // Handle scope changes
            if (sol && top(state).type == "py") {
                var scopeOffset = top(state).offset;
                if (stream.eatSpace()) {
                    var lineOffset = stream.indentation();
                    if (lineOffset > scopeOffset)
                        pushPyScope(state);
                    else if (lineOffset < scopeOffset && dedent(stream, state) && stream.peek() != "#")
                        state.errorToken = true;
                    return null;
                } else {
                    var style = tokenBaseInner(stream, state);
                    if (scopeOffset > 0 && dedent(stream, state))
                        style += " " + ERRORCLASS;
                    return style;
                }
            }
            return tokenBaseInner(stream, state);
        }

        function tokenBaseInner(stream, state, inFormat) {
            if (stream.eatSpace()) return null;

            // Handle Comments
            if (!inFormat && stream.match(/^#.*/)) return "comment";

            // Handle Number Literals
            if (stream.match(/^[0-9\.]/, false)) {
                var floatLiteral = false;
                // Floats
                if (stream.match(/^[\d_]*\.\d+(e[\+\-]?\d+)?/i)) { floatLiteral = true; }
                if (stream.match(/^[\d_]+\.\d*/)) { floatLiteral = true; }
                if (stream.match(/^\.\d+/)) { floatLiteral = true; }
                if (floatLiteral) {
                    // Float literals may be "imaginary"
                    stream.eat(/J/i);
                    return "number";
                }
                // Integers
                var intLiteral = false;
                // Hex
                if (stream.match(/^0x[0-9a-f_]+/i)) intLiteral = true;
                // Binary
                if (stream.match(/^0b[01_]+/i)) intLiteral = true;
                // Octal
                if (stream.match(/^0o[0-7_]+/i)) intLiteral = true;
                // Decimal
                if (stream.match(/^[1-9][\d_]*(e[\+\-]?[\d_]+)?/)) {
                    // Decimal literals may be "imaginary"
                    stream.eat(/J/i);
                    // TODO - Can you have imaginary longs?
                    intLiteral = true;
                }
                // Zero by itself with no other piece of number.
                if (stream.match(/^0(?![\dx])/i)) intLiteral = true;
                if (intLiteral) {
                    // Integer literals may be "long"
                    stream.eat(/L/i);
                    return "number";
                }
            }

            // Handle Strings
            if (stream.match(stringPrefixes)) {
                var isFmtString = stream.current().toLowerCase().indexOf('f') !== -1;
                if (!isFmtString) {
                    state.tokenize = tokenStringFactory(stream.current(), state.tokenize);
                    return state.tokenize(stream, state);
                } else {
                    state.tokenize = formatStringFactory(stream.current(), state.tokenize);
                    return state.tokenize(stream, state);
                }
            }

            for (var i = 0; i < operators.length; i++)
                if (stream.match(operators[i])) return "operator"

            if (stream.match(delimiters)) return "punctuation";

            if (state.lastToken == "." && stream.match(identifiers))
                return "property";

            if (stream.match(keywords) || stream.match(wordOperators))
                return "keyword";

            if (stream.match(builtins))
                return "builtin";

            if (stream.match(/^(self|cls)\b/))
                return "variable-2";

            if (stream.match(identifiers)) {
                if (state.lastToken == "def" || state.lastToken == "class")
                    return "def";
                return "variable";
            }

            // Handle non-detected items
            stream.next();
            return inFormat ? null :ERRORCLASS;
        }

        function formatStringFactory(delimiter, tokenOuter) {
            while ("rubf".indexOf(delimiter.charAt(0).toLowerCase()) >= 0)
                delimiter = delimiter.substr(1);

            var singleline = delimiter.length == 1;
            var OUTCLASS = "string";

            function tokenNestedExpr(depth) {
                return function(stream, state) {
                    var inner = tokenBaseInner(stream, state, true)
                    if (inner == "punctuation") {
                        if (stream.current() == "{") {
                            state.tokenize = tokenNestedExpr(depth + 1)
                        } else if (stream.current() == "}") {
                            if (depth > 1) state.tokenize = tokenNestedExpr(depth - 1)
                            else state.tokenize = tokenString
                        }
                    }
                    return inner
                }
            }

            function tokenString(stream, state) {
                while (!stream.eol()) {
                    stream.eatWhile(/[^'"\{\}\\]/);
                    if (stream.eat("\\")) {
                        stream.next();
                        if (singleline && stream.eol())
                            return OUTCLASS;
                    } else if (stream.match(delimiter)) {
                        state.tokenize = tokenOuter;
                        return OUTCLASS;
                    } else if (stream.match('{{')) {
                        // ignore {{ in f-str
                        return OUTCLASS;
                    } else if (stream.match('{', false)) {
                        // switch to nested mode
                        state.tokenize = tokenNestedExpr(0)
                        if (stream.current()) return OUTCLASS;
                        else return state.tokenize(stream, state)
                    } else if (stream.match('}}')) {
                        return OUTCLASS;
                    } else if (stream.match('}')) {
                        // single } in f-string is an error
                        return ERRORCLASS;
                    } else {
                        stream.eat(/['"]/);
                    }
                }
                if (singleline) {
                    if (parserConf.singleLineStringErrors)
                        return ERRORCLASS;
                    else
                        state.tokenize = tokenOuter;
                }
                return OUTCLASS;
            }
            tokenString.isString = true;
            return tokenString;
        }

        function tokenStringFactory(delimiter, tokenOuter) {
            while ("rubf".indexOf(delimiter.charAt(0).toLowerCase()) >= 0)
                delimiter = delimiter.substr(1);

            var singleline = delimiter.length == 1;
            var OUTCLASS = "string";

            function tokenString(stream, state) {
                while (!stream.eol()) {
                    stream.eatWhile(/[^'"\\]/);
                    if (stream.eat("\\")) {
                        stream.next();
                        if (singleline && stream.eol())
                            return OUTCLASS;
                    } else if (stream.match(delimiter)) {
                        state.tokenize = tokenOuter;
                        return OUTCLASS;
                    } else {
                        stream.eat(/['"]/);
                    }
                }
                if (singleline) {
                    if (parserConf.singleLineStringErrors)
                        return ERRORCLASS;
                    else
                        state.tokenize = tokenOuter;
                }
                return OUTCLASS;
            }
            tokenString.isString = true;
            return tokenString;
        }

        function pushPyScope(state) {
            while (top(state).type != "py") state.scopes.pop()
            state.scopes.push({offset: top(state).offset + conf.indentUnit,
                type: "py",
                align: null})
        }

        function pushBracketScope(stream, state, type) {
            var align = stream.match(/^[\s\[\{\(]*(?:#|$)/, false) ? null : stream.column() + 1
            state.scopes.push({offset: state.indent + hangingIndent,
                type: type,
                align: align})
        }

        function dedent(stream, state) {
            var indented = stream.indentation();
            while (state.scopes.length > 1 && top(state).offset > indented) {
                if (top(state).type != "py") return true;
                state.scopes.pop();
            }
            return top(state).offset != indented;
        }

        function tokenLexer(stream, state) {
            if (stream.sol()) {
                state.beginningOfLine = true;
                state.dedent = false;
            }

            var style = state.tokenize(stream, state);
            var current = stream.current();

            // Handle decorators
            if (state.beginningOfLine && current == "@")
                return stream.match(identifiers, false) ? "meta" : py3 ? "operator" : ERRORCLASS;

            if (/\S/.test(current)) state.beginningOfLine = false;

            if ((style == "variable" || style == "builtin")
                && state.lastToken == "meta")
                style = "meta";

            // Handle scope changes.
            if (current == "pass" || current == "return")
                state.dedent = true;

            if (current == "lambda") state.lambda = true;
            if (current == ":" && !state.lambda && top(state).type == "py" && stream.match(/^\s*(?:#|$)/, false))
                pushPyScope(state);

            if (current.length == 1 && !/string|comment/.test(style)) {
                var delimiter_index = "[({".indexOf(current);
                if (delimiter_index != -1)
                    pushBracketScope(stream, state, "])}".slice(delimiter_index, delimiter_index+1));

                delimiter_index = "])}".indexOf(current);
                if (delimiter_index != -1) {
                    if (top(state).type == current) state.indent = state.scopes.pop().offset - hangingIndent
                    else return ERRORCLASS;
                }
            }
            if (state.dedent && stream.eol() && top(state).type == "py" && state.scopes.length > 1)
                state.scopes.pop();

            return style;
        }

        var external = {
            startState: function(basecolumn) {
                return {
                    tokenize: tokenBase,
                    scopes: [{offset: basecolumn || 0, type: "py", align: null}],
                    indent: basecolumn || 0,
                    lastToken: null,
                    lambda: false,
                    dedent: 0
                };
            },

            token: function(stream, state) {
                var addErr = state.errorToken;
                if (addErr) state.errorToken = false;
                var style = tokenLexer(stream, state);

                if (style && style != "comment")
                    state.lastToken = (style == "keyword" || style == "punctuation") ? stream.current() : style;
                if (style == "punctuation") style = null;

                if (stream.eol() && state.lambda)
                    state.lambda = false;
                return addErr ? style + " " + ERRORCLASS : style;
            },

            indent: function(state, textAfter) {
                if (state.tokenize != tokenBase)
                    return state.tokenize.isString ? CodeMirror.Pass : 0;

                var scope = top(state)
                var closing = scope.type == textAfter.charAt(0) ||
                    scope.type == "py" && !state.dedent && /^(else:|elif |except |finally:)/.test(textAfter)
                if (scope.align != null)
                    return scope.align - (closing ? 1 : 0)
                else
                    return scope.offset - (closing ? hangingIndent : 0)
            },

            electricInput: /^\s*([\}\]\)]|else:|elif |except |finally:)$/,
            closeBrackets: {triples: "'\""},
            lineComment: "#",
            fold: "indent"
        };
        return external;
    });

    CodeMirror.defineMIME("text/x-python", "python");

    var words = function(str) { return str.split(" "); };

    CodeMirror.defineMIME("text/x-cython", {
        name: "python",
        extra_keywords: words("by cdef cimport cpdef ctypedef enum except "+
            "extern gil include nogil property public "+
            "readonly struct union DEF IF ELIF ELSE")
    });

});
